Water-based resin dispersion and process for the production thereof

Abstract

PCT No. PCT/JP96/03680 Sec. 371 Date Aug. 4, 1997 Sec. 102(e) Date Aug. 4, 1997 PCT Filed Dec. 18, 1996 PCT Pub. No. WO97/22641 PCT Pub. Date Jun. 26, 1997A water-based resin dispersion having excellent durability against water, obtained by radical-polymerizing a radical-polymerizable ethylenically unsaturated monomer, a dimethylpolysiloxane having a molecule containing a radical-polymerizable unsaturated double bond and a radical-polymerizable monomer of the formula (A) or (B) in the presence of a reactive emulsifier, an oil-soluble polymerization initiator and water, and a process for the production thereof, wherein R1 is (C2H5O)2 or (CH3O)2, and R2 is (C2H5O)3 or (CH3O).

We claim: 
     
       1. A water-based resin dispersion having excellent durability against water, obtained by radical-polymerizing a radical-polymerizable ethylenically unsaturated monomer, a dimethylpolysiloxane having a molecule containing a radical-polymerizable unsaturated double bond and a radical-polymerizable monomer of the formula (A) or (B) in the presence of a reactive emulsifier, an oil-soluble polymerization initiator and water, ##STR11## wherein R 1  is (C 2  H 5  O) 2  or (CH 3  O) 2 , and R 2  is (C 2  H 5  O) 3  or (CH 3  O) 3 . 
     
     
       2. A water-based resin dispersion having excellent durability against water according to claim 1, wherein the water-based resin dispersion is a product obtained by preparing oil drops having a size of 0.5 μm or less from the radical-polymerizable ethylenically unsaturated monomer, the dimethylpolysiloxane having a molecule containing a radical-polymerizable unsaturated double bond and the radical-polymerizable monomer of the formula (A) or (B) and adding the oil drops to a reaction system. 
     
     
       3. A water-based resin dispersion according to claim 1, wherein the water-based resin dispersion has an average particle diameter of 100 nm or less. 
     
     
       4. A water-based resin dispersion according to claim 1, wherein the oil-soluble polymerization initiator has a solubility in water of 0.3% by weight or less. 
     
     
       5. A water-based resin dispersion according to claim 1, wherein the radical-polymerizable ethylenically unsaturated monomer contains an ethylenically unsaturated monomer having a carboxyl group in an amount of 0 to 5% by weight as part of the radical-polymerizable ethylenically unsaturated monomer. 
     
     
       6. A process for the production of a water-based resin dispersion having excellent durability against water, which comprises preparing oil drops from a radical-polymerizable ethylenically unsaturated monomer, a dimethylpolysiloxane having a molecule containing a radical-polymerizable unsaturated double bond and a radical-polymerizable monomer of the formula (A) or (B) and adding the oil drops into water together with a reactive emulsifier and an oil-soluble polymerization initiator to proceed with radial polymerization, ##STR12## wherein R 1  is (C 2  H 5  O) 2  or (CH 3  O) 2 , and R 2  is (C 2  H 5  O) 3  or (CH 3  O) 3 . 
     
     
       7. A process according to claim 6, wherein the oil drops have a diameter of 0.5 μm or less. 
     
     
       8. A process according to claim 6, wherein the oil drops are prepared with a pipeline mixer. 
     
     
       9. A process according to claim 6, wherein part of the reactive emulsifier and part of the oil-soluble polymerization initiator are added to the water in advance and remaining portions of the reactive emulsifier and part of the oil-soluble polymerization initiator are dropwise added in the form of the oil drops. 
     
     
       10. A process according to claim 6, wherein the radical-polymerizable ethylenically unsaturated monomer contains an ethylenically unsaturated monomer having a carboxyl group in an amount of 0 to 5% by weight as part of the radical-polymerizable ethylenically unsaturated monomer. 
     
     
       11. A process according to claim 6, wherein the water-based resin dispersion has an average particle diameter of 100 nm or less. 
     
     
       12. A process according to claim 6, wherein the radical-polymerizable ethylenically unsaturated monomer contains at least one bifunctional monomer selected from ethylene glycol dimethacrylate, diallyl phthalate, divinyl benzene or glycidyl methacrylate, in an amount of 0 to 5% by weight as part of the radical-polymerizable ethylenically unsaturated monomer. 
     
     
       13. A process according to claim 6, wherein the radical-polymerizable ethylenically unsaturated monomer contains at least one monomer having an ethylenically unsaturated group selected from acrylamide, N-methylolacrylamide, hydroxyethyl acrylate, hydroxypropyl acrylate or hydroxyethyl methacrylate, in an amount of 0 to 10% by weight as part of the radical-polymerizable ethylenically unsaturated monomer.